// SPDX-License-Identifier: GPL-2.0-only/* * PS/2 driver library * * Copyright (c) 1999-2002 Vojtech Pavlik * Copyright (c) 2004 Dmitry Torokhov */ #include <linux/delay.h>#include <linux/module.h>#include <linux/sched.h>#include <linux/interrupt.h>#include <linux/input.h>#include <linux/serio.h>#include <linux/i8042.h>#include <linux/libps2.h> #define DRIVER_DESC "PS/2 driver library" MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");MODULE_DESCRIPTION("PS/2 driver library");MODULE_LICENSE("GPL"); static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout, unsigned int max_attempts) __releases(&ps2dev->serio->lock) __acquires(&ps2dev->serio->lock){ int attempt = 0; int error; lockdep_assert_held(&ps2dev->serio->lock); do { ps2dev->nak = 1; ps2dev->flags |= PS2_FLAG_ACK; serio_continue_rx(ps2dev->serio); error = serio_write(ps2dev->serio, byte); if (error) dev_dbg(&ps2dev->serio->dev, "failed to write %#02x: %d\n", byte, error); else wait_event_timeout(ps2dev->wait, !(ps2dev->flags & PS2_FLAG_ACK), msecs_to_jiffies(timeout)); serio_pause_rx(ps2dev->serio); } while (ps2dev->nak == PS2_RET_NAK && ++attempt < max_attempts); ps2dev->flags &= ~PS2_FLAG_ACK; if (!error) { switch (ps2dev->nak) { case 0: break; case PS2_RET_NAK: error = -EAGAIN; break; case PS2_RET_ERR: error = -EPROTO; break; default: error = -EIO; break; } } if (error || attempt > 1) dev_dbg(&ps2dev->serio->dev, "%02x - %d (%x), attempt %d\n", byte, error, ps2dev->nak, attempt); return error;} /* * ps2_sendbyte() sends a byte to the device and waits for acknowledge. * It doesn't handle retransmission, the caller is expected to handle * it when needed. * * ps2_sendbyte() can only be called from a process context. */ int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout){ int retval; serio_pause_rx(ps2dev->serio); retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1); dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak); serio_continue_rx(ps2dev->serio); return retval;}EXPORT_SYMBOL(ps2_sendbyte); void ps2_begin_command(struct ps2dev *ps2dev){ struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; mutex_lock(m);}EXPORT_SYMBOL(ps2_begin_command); void ps2_end_command(struct ps2dev *ps2dev){ struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; mutex_unlock(m);}EXPORT_SYMBOL(ps2_end_command); /* * ps2_drain() waits for device to transmit requested number of bytes * and discards them. */ void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout){ if (maxbytes > sizeof(ps2dev->cmdbuf)) { WARN_ON(1); maxbytes = sizeof(ps2dev->cmdbuf); } ps2_begin_command(ps2dev); serio_pause_rx(ps2dev->serio); ps2dev->flags = PS2_FLAG_CMD; ps2dev->cmdcnt = maxbytes; serio_continue_rx(ps2dev->serio); wait_event_timeout(ps2dev->wait, !(ps2dev->flags & PS2_FLAG_CMD), msecs_to_jiffies(timeout)); ps2_end_command(ps2dev);}EXPORT_SYMBOL(ps2_drain); /* * ps2_is_keyboard_id() checks received ID byte against the list of * known keyboard IDs. */ bool ps2_is_keyboard_id(u8 id_byte){ static const u8 keyboard_ids[] = { 0xab, /* Regular keyboards */ 0xac, /* NCD Sun keyboard */ 0x2b, /* Trust keyboard, translated */ 0x5d, /* Trust keyboard */ 0x60, /* NMB SGI keyboard, translated */ 0x47, /* NMB SGI keyboard */ }; return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;}EXPORT_SYMBOL(ps2_is_keyboard_id); /* * ps2_adjust_timeout() is called after receiving 1st byte of command * response and tries to reduce remaining timeout to speed up command * completion. */ static int ps2_adjust_timeout(struct ps2dev *ps2dev, unsigned int command, unsigned int timeout){ switch (command) { case PS2_CMD_RESET_BAT: /* * Device has sent the first response byte after * reset command, reset is thus done, so we can * shorten the timeout. * The next byte will come soon (keyboard) or not * at all (mouse). */ if (timeout > msecs_to_jiffies(100)) timeout = msecs_to_jiffies(100); break; case PS2_CMD_GETID: /* * Microsoft Natural Elite keyboard responds to * the GET ID command as it were a mouse, with * a single byte. Fail the command so atkbd will * use alternative probe to detect it. */ if (ps2dev->cmdbuf[1] == 0xaa) { serio_pause_rx(ps2dev->serio); ps2dev->flags = 0; serio_continue_rx(ps2dev->serio); timeout = 0; } /* * If device behind the port is not a keyboard there * won't be 2nd byte of ID response. */ if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) { serio_pause_rx(ps2dev->serio); ps2dev->flags = ps2dev->cmdcnt = 0; serio_continue_rx(ps2dev->serio); timeout = 0; } break; default: break; } return timeout;} /* * ps2_command() sends a command and its parameters to the mouse, * then waits for the response and puts it in the param array. * * ps2_command() can only be called from a process context */ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command){ unsigned int timeout; unsigned int send = (command >> 12) & 0xf; unsigned int receive = (command >> 8) & 0xf; int rc; int i; u8 send_param[16]; if (receive > sizeof(ps2dev->cmdbuf)) { WARN_ON(1); return -EINVAL; } if (send && !param) { WARN_ON(1); return -EINVAL; } memcpy(send_param, param, send); serio_pause_rx(ps2dev->serio); ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0; ps2dev->cmdcnt = receive; if (receive && param) for (i = 0; i < receive; i++) ps2dev->cmdbuf[(receive - 1) - i] = param[i]; /* Signal that we are sending the command byte */ ps2dev->flags |= PS2_FLAG_ACK_CMD; /* * Some devices (Synaptics) peform the reset before * ACKing the reset command, and so it can take a long * time before the ACK arrives. */ timeout = command == PS2_CMD_RESET_BAT ? 1000 : 200; rc = ps2_do_sendbyte(ps2dev, command & 0xff, timeout, 2); if (rc) goto out_reset_flags; /* Now we are sending command parameters, if any */ ps2dev->flags &= ~PS2_FLAG_ACK_CMD; for (i = 0; i < send; i++) { rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2); if (rc) goto out_reset_flags; } serio_continue_rx(ps2dev->serio); /* * The reset command takes a long time to execute. */ timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500); timeout = wait_event_timeout(ps2dev->wait, !(ps2dev->flags & PS2_FLAG_CMD1), timeout); if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) { timeout = ps2_adjust_timeout(ps2dev, command, timeout); wait_event_timeout(ps2dev->wait, !(ps2dev->flags & PS2_FLAG_CMD), timeout); } serio_pause_rx(ps2dev->serio); if (param) for (i = 0; i < receive; i++) param[i] = ps2dev->cmdbuf[(receive - 1) - i]; if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) { rc = -EPROTO; goto out_reset_flags; } rc = 0; out_reset_flags: ps2dev->flags = 0; serio_continue_rx(ps2dev->serio); dev_dbg(&ps2dev->serio->dev, "%02x [%*ph] - %x/%08lx [%*ph]\n", command & 0xff, send, send_param, ps2dev->nak, ps2dev->flags, receive, param ?: send_param); /* * ps_command() handles resends itself, so do not leak -EAGAIN * to the callers. */ return rc != -EAGAIN ? rc : -EPROTO;}EXPORT_SYMBOL(__ps2_command); int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command){ int rc; ps2_begin_command(ps2dev); rc = __ps2_command(ps2dev, param, command); ps2_end_command(ps2dev); return rc;}EXPORT_SYMBOL(ps2_command); /* * ps2_sliced_command() sends an extended PS/2 command to the mouse * using sliced syntax, understood by advanced devices, such as Logitech * or Synaptics touchpads. The command is encoded as: * 0xE6 0xE8 rr 0xE8 ss 0xE8 tt 0xE8 uu where (rr*64)+(ss*16)+(tt*4)+uu * is the command. */ int ps2_sliced_command(struct ps2dev *ps2dev, u8 command){ int i; int retval; ps2_begin_command(ps2dev); retval = __ps2_command(ps2dev, NULL, PS2_CMD_SETSCALE11); if (retval) goto out; for (i = 6; i >= 0; i -= 2) { u8 d = (command >> i) & 3; retval = __ps2_command(ps2dev, &d, PS2_CMD_SETRES); if (retval) break; } out: dev_dbg(&ps2dev->serio->dev, "%02x - %d\n", command, retval); ps2_end_command(ps2dev); return retval;}EXPORT_SYMBOL(ps2_sliced_command); /* * ps2_init() initializes ps2dev structure */ void ps2_init(struct ps2dev *ps2dev, struct serio *serio){ mutex_init(&ps2dev->cmd_mutex); lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth); init_waitqueue_head(&ps2dev->wait); ps2dev->serio = serio;}EXPORT_SYMBOL(ps2_init); /* * ps2_handle_ack() is supposed to be used in interrupt handler * to properly process ACK/NAK of a command from a PS/2 device. */ bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data){ switch (data) { case PS2_RET_ACK: ps2dev->nak = 0; break; case PS2_RET_NAK: ps2dev->flags |= PS2_FLAG_NAK; ps2dev->nak = PS2_RET_NAK; break; case PS2_RET_ERR: if (ps2dev->flags & PS2_FLAG_NAK) { ps2dev->flags &= ~PS2_FLAG_NAK; ps2dev->nak = PS2_RET_ERR; break; } fallthrough; /* * Workaround for mice which don't ACK the Get ID command. * These are valid mouse IDs that we recognize. */ case 0x00: case 0x03: case 0x04: if (ps2dev->flags & PS2_FLAG_WAITID) { ps2dev->nak = 0; break; } fallthrough; default: /* * Do not signal errors if we get unexpected reply while * waiting for an ACK to the initial (first) command byte: * the device might not be quiesced yet and continue * delivering data. * Note that we reset PS2_FLAG_WAITID flag, so the workaround * for mice not acknowledging the Get ID command only triggers * on the 1st byte; if device spews data we really want to see * a real ACK from it. */ dev_dbg(&ps2dev->serio->dev, "unexpected %#02x\n", data); ps2dev->flags &= ~PS2_FLAG_WAITID; return ps2dev->flags & PS2_FLAG_ACK_CMD; } if (!ps2dev->nak) { ps2dev->flags &= ~PS2_FLAG_NAK; if (ps2dev->cmdcnt) ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1; } ps2dev->flags &= ~PS2_FLAG_ACK; wake_up(&ps2dev->wait); if (data != PS2_RET_ACK) ps2_handle_response(ps2dev, data); return true;}EXPORT_SYMBOL(ps2_handle_ack); /* * ps2_handle_response() is supposed to be used in interrupt handler * to properly store device's response to a command and notify process * waiting for completion of the command. */ bool ps2_handle_response(struct ps2dev *ps2dev, u8 data){ if (ps2dev->cmdcnt) ps2dev->cmdbuf[--ps2dev->cmdcnt] = data; if (ps2dev->flags & PS2_FLAG_CMD1) { ps2dev->flags &= ~PS2_FLAG_CMD1; if (ps2dev->cmdcnt) wake_up(&ps2dev->wait); } if (!ps2dev->cmdcnt) { ps2dev->flags &= ~PS2_FLAG_CMD; wake_up(&ps2dev->wait); } return true;}EXPORT_SYMBOL(ps2_handle_response); void ps2_cmd_aborted(struct ps2dev *ps2dev){ if (ps2dev->flags & PS2_FLAG_ACK) ps2dev->nak = 1; if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD)) wake_up(&ps2dev->wait); /* reset all flags except last nack */ ps2dev->flags &= PS2_FLAG_NAK;}EXPORT_SYMBOL(ps2_cmd_aborted);
// SPDX-License-Identifier: GPL-2.0-only
/*
* PS/2 driver library
*
* Copyright (c) 1999-2002 Vojtech Pavlik
* Copyright (c) 2004 Dmitry Torokhov
*/
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/i8042.h>
#include <linux/libps2.h>
#define DRIVER_DESC "PS/2 driver library"
MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
MODULE_DESCRIPTION("PS/2 driver library");
MODULE_LICENSE("GPL");
static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte,
unsigned int timeout, unsigned int max_attempts)
__releases(&ps2dev->serio->lock) __acquires(&ps2dev->serio->lock)
{
int attempt = 0;
int error;
lockdep_assert_held(&ps2dev->serio->lock);
do {
ps2dev->nak = 1;
ps2dev->flags |= PS2_FLAG_ACK;
serio_continue_rx(ps2dev->serio);
error = serio_write(ps2dev->serio, byte);
if (error)
dev_dbg(&ps2dev->serio->dev,
"failed to write %#02x: %d\n", byte, error);
else
wait_event_timeout(ps2dev->wait,
!(ps2dev->flags & PS2_FLAG_ACK),
msecs_to_jiffies(timeout));
serio_pause_rx(ps2dev->serio);
} while (ps2dev->nak == PS2_RET_NAK && ++attempt < max_attempts);
ps2dev->flags &= ~PS2_FLAG_ACK;
if (!error) {
switch (ps2dev->nak) {
case 0:
break;
case PS2_RET_NAK:
error = -EAGAIN;
break;
case PS2_RET_ERR:
error = -EPROTO;
break;
default:
error = -EIO;
break;
}
}
if (error || attempt > 1)
dev_dbg(&ps2dev->serio->dev,
"%02x - %d (%x), attempt %d\n",
byte, error, ps2dev->nak, attempt);
return error;
}
/*
* ps2_sendbyte() sends a byte to the device and waits for acknowledge.
* It doesn't handle retransmission, the caller is expected to handle
* it when needed.
*
* ps2_sendbyte() can only be called from a process context.
*/
int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
{
int retval;
serio_pause_rx(ps2dev->serio);
retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1);
dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak);
serio_continue_rx(ps2dev->serio);
return retval;
}
EXPORT_SYMBOL(ps2_sendbyte);
void ps2_begin_command(struct ps2dev *ps2dev)
{
struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
mutex_lock(m);
}
EXPORT_SYMBOL(ps2_begin_command);
void ps2_end_command(struct ps2dev *ps2dev)
{
struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
mutex_unlock(m);
}
EXPORT_SYMBOL(ps2_end_command);
/*
* ps2_drain() waits for device to transmit requested number of bytes
* and discards them.
*/
void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout)
{
if (maxbytes > sizeof(ps2dev->cmdbuf)) {
WARN_ON(1);
maxbytes = sizeof(ps2dev->cmdbuf);
}
ps2_begin_command(ps2dev);
serio_pause_rx(ps2dev->serio);
ps2dev->flags = PS2_FLAG_CMD;
ps2dev->cmdcnt = maxbytes;
serio_continue_rx(ps2dev->serio);
wait_event_timeout(ps2dev->wait,
!(ps2dev->flags & PS2_FLAG_CMD),
msecs_to_jiffies(timeout));
ps2_end_command(ps2dev);
}
EXPORT_SYMBOL(ps2_drain);
/*
* ps2_is_keyboard_id() checks received ID byte against the list of
* known keyboard IDs.
*/
bool ps2_is_keyboard_id(u8 id_byte)
{
static const u8 keyboard_ids[] = {
0xab, /* Regular keyboards */
0xac, /* NCD Sun keyboard */
0x2b, /* Trust keyboard, translated */
0x5d, /* Trust keyboard */
0x60, /* NMB SGI keyboard, translated */
0x47, /* NMB SGI keyboard */
};
return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
}
EXPORT_SYMBOL(ps2_is_keyboard_id);
/*
* ps2_adjust_timeout() is called after receiving 1st byte of command
* response and tries to reduce remaining timeout to speed up command
* completion.
*/
static int ps2_adjust_timeout(struct ps2dev *ps2dev,
unsigned int command, unsigned int timeout)
{
switch (command) {
case PS2_CMD_RESET_BAT:
/*
* Device has sent the first response byte after
* reset command, reset is thus done, so we can
* shorten the timeout.
* The next byte will come soon (keyboard) or not
* at all (mouse).
*/
if (timeout > msecs_to_jiffies(100))
timeout = msecs_to_jiffies(100);
break;
case PS2_CMD_GETID:
/*
* Microsoft Natural Elite keyboard responds to
* the GET ID command as it were a mouse, with
* a single byte. Fail the command so atkbd will
* use alternative probe to detect it.
*/
if (ps2dev->cmdbuf[1] == 0xaa) {
serio_pause_rx(ps2dev->serio);
ps2dev->flags = 0;
serio_continue_rx(ps2dev->serio);
timeout = 0;
}
/*
* If device behind the port is not a keyboard there
* won't be 2nd byte of ID response.
*/
if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
serio_pause_rx(ps2dev->serio);
ps2dev->flags = ps2dev->cmdcnt = 0;
serio_continue_rx(ps2dev->serio);
timeout = 0;
}
break;
default:
break;
}
return timeout;
}
/*
* ps2_command() sends a command and its parameters to the mouse,
* then waits for the response and puts it in the param array.
*
* ps2_command() can only be called from a process context
*/
int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
{
unsigned int timeout;
unsigned int send = (command >> 12) & 0xf;
unsigned int receive = (command >> 8) & 0xf;
int rc;
int i;
u8 send_param[16];
if (receive > sizeof(ps2dev->cmdbuf)) {
WARN_ON(1);
return -EINVAL;
}
if (send && !param) {
WARN_ON(1);
return -EINVAL;
}
memcpy(send_param, param, send);
serio_pause_rx(ps2dev->serio);
ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
ps2dev->cmdcnt = receive;
if (receive && param)
for (i = 0; i < receive; i++)
ps2dev->cmdbuf[(receive - 1) - i] = param[i];
/* Signal that we are sending the command byte */
ps2dev->flags |= PS2_FLAG_ACK_CMD;
/*
* Some devices (Synaptics) peform the reset before
* ACKing the reset command, and so it can take a long
* time before the ACK arrives.
*/
timeout = command == PS2_CMD_RESET_BAT ? 1000 : 200;
rc = ps2_do_sendbyte(ps2dev, command & 0xff, timeout, 2);
if (rc)
goto out_reset_flags;
/* Now we are sending command parameters, if any */
ps2dev->flags &= ~PS2_FLAG_ACK_CMD;
for (i = 0; i < send; i++) {
rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2);
if (rc)
goto out_reset_flags;
}
serio_continue_rx(ps2dev->serio);
/*
* The reset command takes a long time to execute.
*/
timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
timeout = wait_event_timeout(ps2dev->wait,
!(ps2dev->flags & PS2_FLAG_CMD1), timeout);
if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {
timeout = ps2_adjust_timeout(ps2dev, command, timeout);
wait_event_timeout(ps2dev->wait,
!(ps2dev->flags & PS2_FLAG_CMD), timeout);
}
serio_pause_rx(ps2dev->serio);
if (param)
for (i = 0; i < receive; i++)
param[i] = ps2dev->cmdbuf[(receive - 1) - i];
if (ps2dev->cmdcnt &&
(command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) {
rc = -EPROTO;
goto out_reset_flags;
}
rc = 0;
out_reset_flags:
ps2dev->flags = 0;
serio_continue_rx(ps2dev->serio);
dev_dbg(&ps2dev->serio->dev,
"%02x [%*ph] - %x/%08lx [%*ph]\n",
command & 0xff, send, send_param,
ps2dev->nak, ps2dev->flags,
receive, param ?: send_param);
/*
* ps_command() handles resends itself, so do not leak -EAGAIN
* to the callers.
*/
return rc != -EAGAIN ? rc : -EPROTO;
}
EXPORT_SYMBOL(__ps2_command);
int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
{
int rc;
ps2_begin_command(ps2dev);
rc = __ps2_command(ps2dev, param, command);
ps2_end_command(ps2dev);
return rc;
}
EXPORT_SYMBOL(ps2_command);
/*
* ps2_sliced_command() sends an extended PS/2 command to the mouse
* using sliced syntax, understood by advanced devices, such as Logitech
* or Synaptics touchpads. The command is encoded as:
* 0xE6 0xE8 rr 0xE8 ss 0xE8 tt 0xE8 uu where (rr*64)+(ss*16)+(tt*4)+uu
* is the command.
*/
int ps2_sliced_command(struct ps2dev *ps2dev, u8 command)
{
int i;
int retval;
ps2_begin_command(ps2dev);
retval = __ps2_command(ps2dev, NULL, PS2_CMD_SETSCALE11);
if (retval)
goto out;
for (i = 6; i >= 0; i -= 2) {
u8 d = (command >> i) & 3;
retval = __ps2_command(ps2dev, &d, PS2_CMD_SETRES);
if (retval)
break;
}
out:
dev_dbg(&ps2dev->serio->dev, "%02x - %d\n", command, retval);
ps2_end_command(ps2dev);
return retval;
}
EXPORT_SYMBOL(ps2_sliced_command);
/*
* ps2_init() initializes ps2dev structure
*/
void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
{
mutex_init(&ps2dev->cmd_mutex);
lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
init_waitqueue_head(&ps2dev->wait);
ps2dev->serio = serio;
}
EXPORT_SYMBOL(ps2_init);
/*
* ps2_handle_ack() is supposed to be used in interrupt handler
* to properly process ACK/NAK of a command from a PS/2 device.
*/
bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data)
{
switch (data) {
case PS2_RET_ACK:
ps2dev->nak = 0;
break;
case PS2_RET_NAK:
ps2dev->flags |= PS2_FLAG_NAK;
ps2dev->nak = PS2_RET_NAK;
break;
case PS2_RET_ERR:
if (ps2dev->flags & PS2_FLAG_NAK) {
ps2dev->flags &= ~PS2_FLAG_NAK;
ps2dev->nak = PS2_RET_ERR;
break;
}
fallthrough;
/*
* Workaround for mice which don't ACK the Get ID command.
* These are valid mouse IDs that we recognize.
*/
case 0x00:
case 0x03:
case 0x04:
if (ps2dev->flags & PS2_FLAG_WAITID) {
ps2dev->nak = 0;
break;
}
fallthrough;
default:
/*
* Do not signal errors if we get unexpected reply while
* waiting for an ACK to the initial (first) command byte:
* the device might not be quiesced yet and continue
* delivering data.
* Note that we reset PS2_FLAG_WAITID flag, so the workaround
* for mice not acknowledging the Get ID command only triggers
* on the 1st byte; if device spews data we really want to see
* a real ACK from it.
*/
dev_dbg(&ps2dev->serio->dev, "unexpected %#02x\n", data);
ps2dev->flags &= ~PS2_FLAG_WAITID;
return ps2dev->flags & PS2_FLAG_ACK_CMD;
}
if (!ps2dev->nak) {
ps2dev->flags &= ~PS2_FLAG_NAK;
if (ps2dev->cmdcnt)
ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
}
ps2dev->flags &= ~PS2_FLAG_ACK;
wake_up(&ps2dev->wait);
if (data != PS2_RET_ACK)
ps2_handle_response(ps2dev, data);
return true;
}
EXPORT_SYMBOL(ps2_handle_ack);
/*
* ps2_handle_response() is supposed to be used in interrupt handler
* to properly store device's response to a command and notify process
* waiting for completion of the command.
*/
bool ps2_handle_response(struct ps2dev *ps2dev, u8 data)
{
if (ps2dev->cmdcnt)
ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
if (ps2dev->flags & PS2_FLAG_CMD1) {
ps2dev->flags &= ~PS2_FLAG_CMD1;
if (ps2dev->cmdcnt)
wake_up(&ps2dev->wait);
}
if (!ps2dev->cmdcnt) {
ps2dev->flags &= ~PS2_FLAG_CMD;
wake_up(&ps2dev->wait);
}
return true;
}
EXPORT_SYMBOL(ps2_handle_response);
void ps2_cmd_aborted(struct ps2dev *ps2dev)
{
if (ps2dev->flags & PS2_FLAG_ACK)
ps2dev->nak = 1;
if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
wake_up(&ps2dev->wait);
/* reset all flags except last nack */
ps2dev->flags &= PS2_FLAG_NAK;
}
EXPORT_SYMBOL(ps2_cmd_aborted);